Effects Of Different Tillage Measures On Soil Microbial Functional Diversity Of The Loess Plateau In Central Of Gansu

The research work,the Biolog-ECO plates(Biolog,USA)were conducted to explore the effects of different tillage measures on spring wheat and field pea of soil microbial functional diversity,four types of tillage practices[T(conventional tillage with no straw),NT(no-tillage with no straw mulching),TS(conventional tillage with straw incorporation),NTS(no-tillage with straw mulching)]and three types of soil layer(0~5cm,5~10cm,10~30cm)were conducted in a phased rotation system with spring wheat and field pea in the Loess Plateau in central of Gan Su.So as to provide scientific basis for establishing reasonable farming methods,improving productivity and reducing soil erosion and so on to promote the benign development of agroecosystem.The results show that:(1)The average well color development(AWCD)increased with the increase of incubation time,Carbon source gradually be used to varying degrees,soil microbial use of carbon source capacity gradually increased,the culture curve was "S" type growth.Before sowing and after harvesting the crop,which in the different tillage measures,the change trend of soil microbial AWCD under field pea was NTS> NT> TS > T;The change trend of soil microbial AWCD under spring wheat was NTS> NT > TS> T.The results showed that the no-tillage straw mulching treatment had a significant effect on the whole activity of soil microbes in field pea and spring wheat.(2)NTS and NT treatment could significantly improve soil microbial Shannon-Wiener index(H'),Mc Intosh index(U)and Substrate richness index(S)before sowing and after harvesting in spring wheat;NT and TS treatment had a significant improve on the Mc Intosh index(U)and Substrate richness index(S)of soil microbial community in before sowing and after harvesting of field pea.(3)In different soil layers AWCD in the before sowing and after harvesting,the spring wheat showed5 ~ 10cm> 0 ~ 5cm> 10 ~ 30cm;and the field pea showed 0 ~ 5cm> 5 ~ 10cm> 10 ~ 30 cm.(4)In different soil layers the soil microbial community Shannon-Wiener index(H'),McIntosh index(U)and Substrate richness index(S)in before sowing and after harvesting,the spring wheat showed5 ~ 10cm> 0 ~ 5cm> 10 ~ 30cm;and the field pea showed 0 ~ 5cm> 5 ~ 10cm> 10 ~ 30 cm.(5)The effects of soil microbes on single carbon sources were different under different treatments,and the no-tillage measures and straw measures were the main influencing factors in the before sowing and after harvesting of spring wheat and field pea.(6)Carboxylic acids,amino acids carbon sources are the main carbon sources for the use of soil microbes in the before sowing of field pea;Carboxylic acids,amino acids and Carbohydraytes carbon sources are the main carbon sources for the use of soil microbes in the after harvesting of field pea.Carbohydrate carbon source is the main carbon source for distinguishing straw treatment(NTS,TS)and non-straw treatment(T,NT);amino acids and carboxylic acid carbon sources are the main carbon source for distinguishing tillage treatments(T,TS)and no-tillage treatments(NT?NTS).(7)Carbohydrates,amino acids,and carboxylic acids carbon sources are the main carbon sources for the use of soil microbes in the before sowing of spring wheat;Carbohydrates,Amines and Amino acids carbon sources are the main carbon sources for the use of soil microbes in the after harvesting of spring wheat.Carbohydrate carbon source is the main carbon sources for distinguishing tillage treatments(T,TS)and no-tillage(NT,NTS);amino acid carbon sources are the main carbon sources for distinguishing straw treatment(NTS,TS)and non-straw treatment(T,NT).